This enzyme belongs to the family of hydrolases, specifically those glycosidases that hydrolyse O- and S-glycosyl compounds. The systematic name of this enzyme class is D-galactosyl-3-(N-acetyl-beta-D-galactosaminyl)-L-serine mucinaminohydrolase. Other names in common use include endo-alpha-N-acetylgalactosaminidase, and endo-alpha-N-acetyl-D-galactosaminidase.